Open Main Menu and go to Trading Dashboard.
Locate the Watchlist panel. By default, it's at the middle top of your dashboard.
Check the product you want to add to your dashboard here, then click Manage again to close the dropdown list.
Locate the Accounts panel (top left of dashboard by default). Click Manage and check if both base currency and quote currency of your product are checked. Once you do, click Manage again to close the list.
Locate the Order Entry panel (top left of dashboard by default) and click the product name.
Your product should be on the list now.